Platen-shift mechanism.



PATENTED OCT. 29. 1907.

G. W. CAMPBELL. PLATEN SHIFT MECHANISM.

INVENTOR APPLICATION FILED JAN.15,1907.

WITNESSES.

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GEORGE W. CAMPBELL, OF NEW YORK, N. Y.. LXSSIGNOR, BY i\l fCSNl'l ASSTGNMENTS. T VICTOR TY fl.\\" R flldli (031 l.\ N Y.

PLATEN-SHIFT MECHANISM Specification of Letters Patent.

Patented Oct. 29, 1907'.

Application filed January 15. 1907. Serial No. 352.375.

To all whom it may concern:

Be it known that I, GEORGE W. Canrnnnt, a citizen of the United States, resident of the borough of Manhattn, city, county, and State of New York, have in vented new and useful Improvements in Flatten-Shift lllechanisin. of wlr-ch the following is a specification.

The present invention pertains to the platen shift mechanism I of typewriting machines, the principal features of which are, that the shifting mechanism for the platen and the lever-system for keeping the platen in alinement while being shifted, are combined in one lever systeni, operated by the shifting key; and that the rebound of the paten, after shifting, is prevented. The device is shown in the drawings where:

- Figure l is aside elevation of a part of the typewriting machine. showing the novel device in connection with the carriage. Fig. 2 is a front sectional eltn'ation of a part of the machine frame, showing, how the bellcrank, operating the device, is disposed therein. Fig. 3 is a front elevation of the platen-supporting device. Fig. 4 is a front elevation of the locking-devicefor the shifting mechanism. Fig. 5 is a plan view of the not ch, holding the shift-key in the shifted position.

In Fig. l, the part of the machine frame on vhich the carriage 2-is slidinglyai' ranged between the rails 3 and 4 by means of the bzills 5 The platen is suspended on each end by the h brackets or links 8, of whichonly one is shown in i the drawing, said brackets being escillatingly fastened on the rod 7 (shown in dotted lines) extending between and fastened to the lugs-t) of carriage 2. The. w eight of the platen may be count erbalauccd by any well-known suitable. means, as for instance by a coil spring on rod '7 not shown'in the drawing). The center pin- 6 of the platen is led on each side r0 tatably through the crosashapetil end l'rainc l5. whi h end framediears on each side the well known ratchet mechanism for revolving, the platen (not shown in the drawing), and is held together by rod lo. tn the middie of rod l6 is fastened frame l7 (Figs. l, f!) lay-pins 13. which frame carries on its underside the roll it) suitably shaped to roll on the cylindrical rail 30.

In parallel to th platen within the machine frame 1 is disposed the pivot -rod 2l, Figs. 1,2. pivoted on the screws 22 on each end and bearing on each end a bell-- having bn its end a groove suitably shaped to receive other arm of each bell-crank is provided with a pin l l l the hook-shaped end of pull-rod 31.

led with t" E.

' length of link A D of the system iii-certain proportion to In a suitable place on the machine frame is provided the lug 33 bearing pivot shaft 34 on which rocking bellcrank 32 is fastened. To one arm of this bell-crank is linked pull-rod til, to the other arm pulla'od 36, which in turn is linked to the shiftkey-bar It will be seen that if shift keybar is pressed downwardly the rocking of bell-crank 32 will cause pull-rod 3'1 to rock dwll-crank 23, whereby the link system A. B, (1, l) denoted in dash and dot lines will be shifted into the-position A, B, if, D, so that the point E of the platen l0, ftmmerly opposite type 41. of type-bar 40, will be exactly opposite type 42, and.the latter type will strikedln: platen in strict alinenient, because line (1 D is in parallel w ith line D and therefore 0 .C in paral- This effect is obtained by having the the length of link BC, and A D and B C under a certain angle to A B, which may be found by geometrical construction by anyone skilled in the art, assuming hereby 23 by the set-screw -13 and 44, and for bracket 8 by setscrew acting against stop 46. i P

If, in case of writing only capitals, it should be desired to keep the platen l0 permanently in the position indicaled by the dotted circle, the shift-key 48 is pressed down inst end of slliftkey 47. Key 43 is linked to key-bar 235 and held inthc normal position relatively to bar 35, shown in the drawing, by spring Sl, and provided with a nose 49. Besides it is guided in the slot of catch 50 secured in a suitable place on the machine frame. If new key-bar 35 is operated through key 48 .in the direction of't he arrow, nose 4%) will engage in the catch 50 and thus kecp key-bar 35.locked in the down position, corresponding to the shifted position of the platen for writing capitals. For returning the platen. to its normal position, shown in the drawing, enough lost downward inotion is provided for the key-bar 35, so that. if key 47 is pressed down further, nose 49 will be released from catch 50 and spring 51 will return key 48 to its normal position relatively to bar If new keybar is released into its normal position, nose 4!) will slide past catch 50 and the platen thus be returned to its normal position.

[t has been found that in iiist'w'riting the.pluten wit i its link system in returningdro its norniill position and thereby striking stop or sctscrew' 43,'will slightly re bound, which may affect the correct alinement. There forea locking device has been provided, which lock the link system each time at thiarnoment it returns to its norytiel position and touches stop 43, and which unlocks the system before the upward shift commences. For

tliis purpose lock-rod 95 is )rovidcd, which journalcd in lug 33 and yielding-1y p. -d by spring 57 againskpin 5b of lj :ll-Clzlill 32'. 0d o5 is of such a length that it: will just touch pin 2-5 of bell-c aiik 23 when the latter is iii its normal position, llierehy preventing even the slightest, rocking motion oi' this in ll-rrank and thus of the whole link system 'nd the platen. it will be, seen 1n ligv that the ho hapcd end ot pull-rod Ill has some lost motion in its normal posit ion (shown by (lottcd lines). During the shitting o eration oi the platen, this lost motion will be taken up iii-st in pr ing down -liar wh reby pin 5t; of hell-crank 332 will slide along lock-rod 55 and lilt its end oil thilpin ol' hullcrank 23, so that; pull-rod 3] can now rock the link s rein. In releasing the shill-key, lock-rod 55 will return to its normal position together \\'llll the link system and lock m ll-crank 213 before the rz-hound can take place.

While tlltshifting o 'ieralion oi' the plate her-n shown in the drawings only on one side 01' the ma .liiiiO, a sliil'tskey and locking dovice of the same ronst riictioii may be. provided on tho otiir side ol' the machine, so that the operator may shift the plaicn i'roiii either side of the keyboard {it will. The lock-rods, of either side wouldliavc to be connected by a common shaft 58, Fig 4, so that the link system is unlocked on both sides when the shift-key of only one side is operated.

Having thus described my invention, ii i claim new, and desire to secure by lictto Patent. is.

i in :i tvpewritinc' in: gliiiie, the comhination with a carriage L','lll(l 3ll rcctiiinearl) longitudinally of the machine. a platen carrying trai'nc, links connectingsaid frame the carriage, lng's on said links near their pivot points, and lue's on the car iage frame aaainsr which said link lu-"s aliut l'or limi[ii1g' the up u'f d motion or said links, a rail on which the platen carrving frame has rolling support independently of the car t 'prs adapted to strike iIllP platen. pivoted bell nl in; their t'orward arr s opcratively connected to s, rail and suji'aoly propor tioned in the leigth of said i'rame connectinglinksand forming wi'rli said links a link l'em to guide the platen so as to have [he same striking point; in the normal and in the shifted position in a plane roiiicidciit'w ,ll the piano through the type faces in their striking position. adjust able stops for limiting the motion o said bell cranks iii Jioth dirccLlons, and means for iriiting said pivoted bcll cranks to shift the platen.

2. In a typewri ing machine, the combination of .a carriage guided rectilincarly li'inuitudinally .ol rho mac. inc. :1 platen carrying frame, l nks iiinectii ,"!i(l i'raiiie lo [.hc carriage. lugs on said links near their pivo o ts having set screws and lugs on the can l'rann. .L which said link set screws ah it l'or limiting the upward motion of said links, a rail on which the platen car in: frame has roiling suppcrt independently of the car: no, types adapted to strike the platen pivoted hell cranks having their t'oru 'ard arms oporativcly connected to said rail and suitably proportioned to the lcir'tlis of said frame connecting links, and t'orniiiiy,- with said links it link system to guide the platen so as to have tlie'srinic striking point in the normal and in the shifted position in a plane coin iii; with the plane through the type fare in their Stl'lliliiu' position. adjustable stops for limiting the motion of said hell cranks in both directions and means for op crating said pivoted bell cranks to shill the platen.

2;. In i typcwritiiig machin kl c combination iii a carriage c'uidcd rcctiliiiearlv longitudinally oi the iiiiicliine, a platen carrving frame, links'conni rtiii illtlll'dllie to the cari ice, lugs on said links near their pivot: point having," set screws, and lugs on the carisaid link set screws-abut ior llllllllig the upward motion ii li a' e l'rziiiic against which of said links, a rail on which the platen carrying frame has rolling support independently of the carriage, types adapted to st ike the platen, pivoted hell cranks having their forward arms operatively connected to said rail and suitaliiy proportioned to the lengths of said frame connecting; links, and forming with said links a link sys-' tem to guide the platen so as to have the same striking point in the normal and in the shifted position in a plane coincident, with the plane tlil'Ollf. l the type t'a es in their striking position, adjustable shops [or limitingthe motion of said bell cranks in both directions, a shift-key, an'intel-mediate hell crank liltl a pull rod, said intermediate bell-crank lining roc-aihly fastened and having one arm suitably linked to said shil't ker and the other arnrdiiiked to one end of the pull rod, the other end of 11d pull rod being suitably connected to the downward arms of the platen shifting bell crank to shift the platen, and means for locking and unlocking the platen in its normal position.

"i. In a typewriting machine, the combination of a cargc guided rert'iliiiearli' longitudinally oi the machine, a platen carryin has rolling support iiidependcntl of the carnage, Ly'pcs adapted't'o strike the platen; pivoted licli cranks having their forward arms operativcly connected to said rail and suitabl iiiroportioncd to the lengths of said frame connect.- ing links and forming with said links a link sysieni to guide the platen so as to have the some striking point in the normal and in the shifted position in a plane coincident with the plane through the type fares in their striking position, adjustable stops for limiting the motion of said ball cranks in both directions, a shift key, an iiitcn mediate boll crank and ii. pull red, said iiiteriiiediatc bell crank being rockably fastened and having one arm suitably linked to said shill y and the other arm linked to one end of the pull rod. the other end of said pull rod having lost motion connection with the downward arms of said platen shitting bcll crank to shirt the platen, and a pin fastened on the pull rod llllrll'lng arm of said intermediate lj'c'll crank. a lock rod pivoted on one and close to said intermediate bell (rank and supported by said pin and pushing against the downward arm 0! said platen sliit'tin" bell crank with its other end, the lost motion of said shirt key operated pull rod causing; said supporting pin to unlock said platen shilling bcll crank liofoi'e the platen is being shil'ied, and to lock said bell crank on the return of the platen to its normal position 5. in a t vpcwriting machine, the combination of a carriage guided rcctiliiicarly longitudinally of the machine, a platen connected to said carriage to accompany i iongit udinal motion having a shittingmovement shitting the platen transversely thereto, pivoted bcll'cranks having one of their ci -'])Ull(llli{ arms opcrativcly connected to said shitting movement, a sliil't. key. an intermediate hell crank and a pull rod, said intermediate bell crank being rockahly fastened and having one arm suitably linked to said shill key'uiid the other arm linkgd to one end of said pull rod, rlie other end of the pull rod having lost-motioncoiiiicrtion with one of the other corresponding arms of said platen-shifting boll cranks to shift the platen, and a pin fastened on the pull-rodlicaring arm oi said inter mediate hcll crank, a lock rod pivoted on one end close to said intermediate licll crank and supported by said pin and pushing against the pull rod connected arm of said [platen shitting; bell cra'nkwitli its other end, the lost mo ticn of l iid siiilc key operated pull rod causing said supporting pin to unlock said platen shitting bell crank be tore the platen is being shifted and to lock said hell crank on the return oi the platen to its normal position,

GEORGE W. CAHlLildillr, 

